JPH0442817A - Magnetic material powder of oxide and its production - Google Patents

Abstract

PURPOSE:To obtain magnetic material powder of magnetoplumbite type oxide having high coercive force by burning a raw material powder, blended to give a chemical composition of specific magnetic material of oxide, in a burning atmosphere. CONSTITUTION:In production of magnetic material powder of oxide, raw material powders are blended to give a chemical composition shown by the formula (n=0-1.5; when 0<=a<=0.05, 0.2<=x<=4.0; when 0.05<=a<=1.0, 0.1<=x<=4.0) and dried to prepare starting powder. Then the starting powder is burnt in a burning atmosphere and made into burnt powder to give the objective magnetic powder. By the above-mentioned production of magnetic material powder, magnetoplunmbite type ferrite (M type ferrite) material wherein Fe2O3 is partially replaced with Al2O3 especially among magnetoplumbite type ferrite can be produced in a wide production range so as to show the same magnetic characteristics.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic material powder, and more particularly to a magnetoblanbite-type oxide magnetic material powder having a high coercive force and a method for producing the same.

[Prior Art] Magnetic materials are generally used in many cases by utilizing high magnetic flux density. However, coercive force is often used primarily. Particularly, when the coercive force (+Hc) is large, there is an advantage that it can be made thinner very easily.

In addition, by changing the Curie temperature of the magnet (mainly to a lower temperature side), the amount of magnetization decreases, and a method of using it as a sensor is also being put into practical use.

In particular, in a magnet containing a polymer resin, it is possible to easily form an extremely thin magnetic layer by bonding magnetic material powder with a polymer resin, etc., so having a high coercive force is
There are advantages.

In addition, in this manufacturing method using polymer resin and magnetic material powder, the space factor of the magnetic powder is lower than that of sintered bodies, etc.
Although it has the disadvantage of low magnetization, it has flexibility, so it can be easily manufactured even in complex shapes, and it can also be easily formed into a thin ribbon by rolling or into a thin film by coating.

On the other hand, processing a sintered body with a thickness of 11 .mu.m or less with high precision requires extremely advanced technology, and processing of a thickness of 100 .mu.m or less becomes extremely difficult. However, these thickness ranges are extremely easy in the field of polymer composite magnetic materials.

On the other hand, as magnetic materials become thinner, the demagnetizing field increases, and materials with low coercive force.

A phenomenon occurs in which the properties as a magnetic material decrease and eventually the two functions cease.

Therefore, in order to make magnetic materials thinner.

Magnetic materials with high coercivity will be useful.

At present, it is a magnetic material with high coercive force.

Rare earth magnet materials such as Sm-Co type Nd-Fe-B type,
There are intermetallic compound materials such as Pt-Co-based and Pt-Fe-based magnets, but these have poor pulverizability and are difficult to obtain into powders with a uniform particle size distribution when used as magnetic powders. Not only that, but it is also a good value.

Furthermore, since rare earth magnet materials are chemically active, if they are used in powdered form, oxidation causes changes over time, such as deterioration of magnetic properties.

In contrast, magnetobrambite-type ferrite magnets (
M type ferrite, general formula MO・6F e2O9. Here, M (Ba, Sr, Pb, etc.) is generally a raw material powder (e.g., BaCO3, SrCO3, Fe2 o3.Fe0
After mixing 0H, A12O3, AN(OH)3, etc.,
It is obtained by firing at a temperature of about 800°C or higher, is inexpensive,
Since it is an active oxide, it is chemically stable.

[Problems to be Solved by the Invention] However, the coercive force of this magnetoblanbite type ferrite magnet is clearly lower than that of the above-mentioned intermetallic compound magnet.

For example, what are the characteristics of sintered magnets currently on the market?

B r is around 4.2 kG, rHc is around 3 kOe.

In addition, this oxide magnet has good crushability, but when crushed to an average particle size of around 1μ, the HC becomes 1k
It decreases to around Oe.

Therefore, the first technical problem of the present invention is to improve the coercive force of magnetobrambite-type ferrite such as stable barium-based and strontium-based ferrite materials at low cost, and to improve the coercive force of oxide magnetic material powder having high coercive force. An object of the present invention is to provide a method for manufacturing the same.

On the other hand, in order to obtain a high Hc, the − part of Fe2O is
i) When replacing with 2Os etc., IHc improves with the amount of substitution, but the temperature at which magnetobrambite ferrite is formed also increases, so it is necessary to sinter at a high temperature to form a single phase of magnetobrambite ferrite. Become.

However, in the high temperature range, even a slight increase in temperature causes significant sintering of the powder. Therefore, to obtain a high coercive force magnetic material that is fine and has a narrow particle size distribution.

Lowering the firing temperature would be extremely useful.

Generally, a method of lowering the firing temperature is to mix a small amount of additives. The reason for this is that when this type of additive is added in large amounts, it diffuses into the magnetobrambite ferrite.

This is to significantly increase both magnetization and coercive force.

On the other hand, it is possible to mix small amounts of additives uniformly.

It is not easy and can be said to be a particularly difficult method. Therefore.

If there are additives or substitutes that can be mixed in large quantities,
Since it becomes possible to tolerate a certain degree of mixing variation, it is very useful industrially.

Therefore, the second technical problem of the present invention is to reduce the firing temperature of a magnetobrambite ferrite material in which part of Fe2O, which is stable and stable magnetobrambite ferrite, is replaced with AN2Oi, by using a large amount of substituted material. An object of the present invention is to provide an oxide magnetic material powder having a high coercive force whose coercive force is improved by mixing, and a method for producing the same.

In addition, ZnO is added to magnetobrambite-type ferrite powder.
In compounds consisting of ZnO as one of the main components, ZnO
As the content of W-type ferrite is increased, W-type ferrite tends to be generated more easily.

Therefore, in order to form a single phase of magnetobrambite-type ferrite, restrictions arise in terms of composition and firing temperature. Therefore, a manufacturing method that can reduce these manufacturing constraints would be extremely useful industrially.

Therefore, the third technical problem of the present invention is to produce an oxide magnetic material with high coercive force in which part of the Fe2O of magnetobrambite ferrite is replaced with A12Ox, under a wide range of manufacturing conditions, and with similar magnetic properties (IHc). ) and a method for producing the same.

[Means for Solving the Problems] According to the present invention, the general formula (1-a) BaO・asro
Conflict (6-n-x) Fez Os
・ xAI 2O,: (However, when n-0 to 1.5 and 0≦8<0.05, 0.2≦x≦4.0,
When 0.05≦8≦1.0, an oxide magnetic material powder having a chemical composition expressed by 0.1≦x≦4.0 is obtained.

According to the present invention, the general formula (1-a) BaO.asrO
・(6-n-x-y z)Fe2O3XAN2O3
・yZnO*zTiO2: (However.

n-0~1.5.0≦y≦1.0.0≦z≦1.0,
0゜1≦y+z≦1.3, 0≦a<0.05, 0,2≦x≦4.0, 0.05≦a≦1.0, 0.1≦x≦4.0 ) A specialized magnetic material powder is obtained, which is characterized by having a chemical composition represented by:

According to the present invention, in the method for producing oxide magnetic material powder, the general formula (1-a) BaO-aSrO (6-n
-x) Fe2Os "XAfI2O3: (However, n-
0 to 1,5, and when 0≦a<0.05, 0゜2≦x
≦4.0, 0.1≦x≦ when 0.05≦a≦1.0
4.0) A preparation step of mixing raw material powders so as to have the chemical composition expressed by 4.0) and drying to prepare a starting powder, and firing the starting powder in a firing atmosphere.

A method for producing an oxide magnetic material powder is obtained, which comprises a firing step of producing fired powder.

According to the second aspect of the present invention, in the method for producing oxide magnetic material powder (iii), A, 92O, in the raw material powder is
A method for producing an oxide magnetic material powder characterized by having an average particle size of 0.005 to 1.0 μm layer is obtained.

According to one aspect of the present invention, there is obtained a method for producing an oxide magnetic material powder, wherein the firing atmosphere contains 50 vol% or more of oxygen.

Further, according to the present invention, in any of the above methods for producing oxide magnetic material powder, after the sintered powder is finely pulverized and mixed, the temperature does not exceed 100°C or more higher than the predetermined sintering temperature. within.

A method for producing oxide magnetic material powder is obtained, which includes a heat treatment step of performing heat treatment.

Furthermore, according to the present invention, according to the method for producing oxide magnetic material powder, the general formula (1-a) BaO・asrO number
(6-n-x-y-z) Fe2o.

xAR2O3: yZnO-zTio2: (However.

n-0~1.5.0≦y≦1.0.0≦z≦1.0,
0゜1≦y+z≦1.3, 0≦a<0.05, 0.2≦x≦4.0, 0.05≦a≦1,0, 0.1≦x≦4,0 ) A preparation step in which raw powders are mixed to have the chemical composition expressed by and dried to prepare a starting powder.

A method for producing an oxide magnetic material powder is obtained, which comprises a firing step of firing the starting powder at a predetermined firing temperature in a firing atmosphere to produce a fired powder.

Further, in the method for producing the oxide magnetic material powder according to the second aspect of the present invention, Al2O3 in the raw material powder is 0°005 to 1.0°.
A method for producing an oxide magnetic material powder characterized by having an average particle size of 0 μm is obtained.

According to one aspect of the present invention, there is obtained a method for producing an oxide magnetic material powder, wherein the firing atmosphere contains 50 vol% or more of oxygen.

Further, according to the present invention, in any of the above methods for producing oxide magnetic material powder, after the sintered powder is finely pulverized and mixed, the temperature does not exceed 100° C. or more higher than the predetermined sintering temperature. within.

A method for producing oxide magnetic material powder is obtained, which includes a heat treatment step of performing heat treatment.

Next, an outline of the present invention will be explained.

Magnetobrambite barium type (hereinafter abbreviated as M-type Ba) ferrite has the general formula Ba0.6Fe2Oi.
, but the region where high magnetic properties can be obtained is BaO.(6-n)Fe2O. (Here n-
0 to 1.5).

Further, as a magnetic material, a value of +Hc5kOe or more was set as a value indicating the characteristics of high coercive force. On the other hand, with the development of magnetic sensing techniques in recent years, the amount of magnetization has changed, and 4πIs of powder is 2O0
Since a value of G or more is practical, the powder must satisfy a value of G or more. Then, it becomes even more useful to replace a part of Fe2OB with AU2Og, and BaO・(6-n-x)Fe2O3
- It was found that x-0.1 to 4.0 is an effective range for xAl2O3.

On the other hand, magnetobrambite-type strontium (hereinafter M
Type S (abbreviated as) type ferrite also has the general formula SrO.
6Fe2O. Although it is expressed as .

As a magnetic material, IH is a value that indicates the characteristics of high coercive force.
C is about 5 koe or more, magnetization is 4πI, about 2O0G
Provided that the above values are satisfied.

It becomes even more useful to replace part of Fe2O3 with Al103, resulting in SrO・(6-n-x)Fe2O3・x
It was found that x-0.1 to 4.0 is an effective range for Al2O3.

Furthermore, the present inventor conducted nine different experiments.

The characteristic values of the above magnetic powder are.

(1) (1-a) BaOΦaSrOφ (6-n-x)
F e2 o3 fist XAl2O3: (here,
n −0 to 1.5), 0≦a<0.05.0
．． 2≦x≦4.0.

(2) (1-a) BaO・aSrO・ (6-n −x
) Fe2O5 ・XAI2Ox: (where n=0 to 1.5), 0.05≦a<1
．． 0, 0.1≦x≦4.0.

(3) The average particle size of p, R2os raw material powder is 0.0
It has been discovered that this can be achieved by setting the volume to 0.05 to 1.0 μl.

In (1) above, the value of x CAR2O3) is 0.2
≦x≦4.0 was set using Ba ferrite powder (a-0
When the magnetic properties of
OE or more, xm4.0 or less is 4π! , is 200G or more.

Further, when a part of BaO is replaced with SrO (when a≠0), similar characteristics can be obtained up to a<0.05. However, when 0.05≦a≦1.0,
As shown in (2) above, x (Ai12O3)
Even if <0.2, if 0.1≦x.

4yr1g when 1Hc is 5 kOe or more and rx-4-0 or less
becomes more than 2O0G, and of course a=1.0. That is.

Even if all BaO is SrO, Hc is 5kOe
As described above, a characteristic in which 4πI8 is 2O0G or more can be obtained.

In addition, the average particle size of the A12Ov raw material powder is 0.005
The reason for setting it within the range of ~1.0 μm is that below 1.0 μm, the reactivity improves and the formation of 2Y type ferrite becomes noticeable, and Hc values exceeding 5 kOe can be obtained, so 0.005 μm The above is one thing in the present invention,
This is because, in addition to the fact that it has been confirmed that the particle size is within this range, it is currently difficult to use powder with a particle size smaller than this on an industrial scale because it causes problems in terms of cost and workability.

However, with this amount of Al2O5 substitution, IH
c is improved, but the temperature at which the 1Y type ferrite single phase is formed also increases, and the magnetic properties of the ferrite powder tend to change significantly depending on the firing temperature.

Therefore, the firing temperature can be lowered to exhibit similar magnetic properties over a wide firing temperature range.

In contrast to the decrease in 4πIs due to A1′2O3 substitution, 4πl
If there is a method that can be expected to increase .

This makes it possible to easily produce a high coercive force Y-type ferrite powder that exhibits small variations and strong magnetic properties, and is extremely useful industrially.

As a result of two different experiments, the present inventor found that by substituting a part of the above composition with ZnO, TiQ2, etc., a Y-type ferrite having high coercive force with similar magnetic properties over a wide firing range could be obtained. .

We also discovered that we can expect an improvement in saturation magnetization.

What is the chemical composition ratio of the Y-type ferrite?

(1-a) BaO dispute aSrO・ (6-n-x-y-z
)Fe2O3 ・xA12Os ・yZnO・zTiO
z: (where n-0~t, 5, a-mO~
When 0°05, xmO, 2 to 4.0, a-”0.
When 05 to 1, X-0, when 1 to 0.3, z -0,1-1
, 0 is useful. where n, a, and X
The range of is due to the same reason as mentioned above, and the reason why z -0,1 to 1,0 is set at y-0 is that when z = 0.1 or more, the amount of change in the magnetic properties of the powder due to the sintering process is This is because it clearly decreases. In addition, the reason why y-0 is zml or less than 0 is because if the content exceeds this, a low IHC heterophase (
This is because the formation of Y-type ferrite) was observed, and a clear decrease in r I HC was observed depending on the firing temperature.

On the other hand, the ranges of n, a, and X are the same as above.

When z-0,y≠0, the chemical composition ratio is (1-a)BaO
-aSrO・(6-n-x-y-z)Fe2O3・x
A#z Os ・yZnO-zTi02: (Here, n
−0 to 1.5. When a-0 to 0.05, X-0, 2 to 4
．． 0, a -0,05~1 when xmO,1~0
It becomes useful in the range of y-0.1 to 1.0 at °3.

Here, the ranges of n, a, and

This is because when y is 0.1 or more, the temperature at which Y-type ferrite is formed is clearly lowered.

The reason why y is set to 0.1 or less is that if the content exceeds this value, the formation of a different phase (W-type ferrite) with low +l HC is observed, and the +Hc decreases significantly.

Furthermore, M-type ferrite containing both ZnO and TiO2 has the chemical composition (1-a) BaO・asro・(
6-n-x-y-z)Fe2O3XAl2O3 ・y
ZnO-zTiO2: (here.

When n 匍 0 to 1,5 and a-0 to 0.05, x-0,2
~4.0, x-0 when a = 0.05 ~ 1.0
, 1-4.0. Furthermore, y≠0. y+z-0 with z≠0
, 1 to 1.3).

Here, the ranges of n, a, and x are based on the same reason as described above, and y≠0. ZnO and TiO are used for z≠O.
This is because the effect is more pronounced when 2 is contained in combination than when 2 is contained alone.

The reason why y+z was limited to within the range of 0.1 to 1.3 is that when y+z is 0.1 or more, the amount of change in the magnetic properties of the powder due to the sintering temperature is clearly reduced, and an improvement in 4πI5 is also expected. Because you can.

On the other hand, the reason why y+z is set to 1.3 or less is that if the content exceeds this value, W-type ferrite will form and coexist when fired in a high temperature range, resulting in a decrease in Hc and stable magnetic properties over a wide firing temperature range. That's what you get.

This is because it becomes difficult.

Furthermore, the effect of containing ZnO and TiO□ in combination is more pronounced than when using them alone, because the coexistence of Zn2+ and Ti'+ can approach M3+ and stabilize the formation of M-type ferrite. We infer that this is to improve performance.

In addition, such S rO-Fe2O3-Ap2O3
-ZnO-T Even if it is an M-type ferrite based on i02, if the ZnO content increases significantly, the temperature will change from 12O0℃ to 13℃.
When fired in air at around 00°C, a W phase is generated, making it difficult to obtain a powder that exhibits homogeneous magnetic properties.

In the present invention, as a result of repeated experiments in order to solve the problem of W-phase bionic acid entering the M-phase, the oxygen content in the firing atmosphere was reduced to 50%.
It has been discovered that by setting the content in the range of ~100 vol %, the generation of W phase during firing can be suppressed and a 1M single phase ferrite powder, particularly Sr-based ferrite, can be obtained.

The reason why the oxygen content is set in the range of 50 to 100 vol% is that if the oxygen content of the firing atmosphere is less than 50 vol%, the atmosphere becomes reducing to the fired powder and the formation of the 9W phase cannot be suppressed. I suspect that there is.

It has also been found that the disappearance of foreign phases and the improvement of lHc can be achieved by pulverizing and mixing the fired powder and then heat-treating the pulverized powder. It is presumed that this is because addition of these treatments improves the diffusion of atoms, thereby improving the homogenization of the crystal structure and promoting the formation of the 1M phase.

It can be said that this heat treatment temperature is practically useful within the range of 850°C to calcination temperature +100°C.

[Example] Embodiments of the present invention will be described with reference to the drawings.

Example 1 Purity is 99.5vt% or more and average particle size is 0.5μm
The following a-Fe2O3. BaCO3 and an average particle size of 0.
005, 0.01.0.05.0.10.0.5Q,
1. Q, 3.0.

Using α-A12O3 of 5.0 μm, the chemical composition ratio is B.
aO'5.3 Fe2O,'0.5 Aj12O. Each was weighed so that Next, these eight types of powder were mixed for 20 hours using a ball mill using ethanol as a dispersion medium, and then dried.

This was held at 1000° C. for 2 hours in the air to produce a fired powder. After crushing these fired powders in a mortar, powder X-ray diffraction and coercive force measurements were performed.

X-ray diffraction revealed unreacted substances (α-Fe2O3. α-A
12O3) and confirmation of the reaction product (M-type Ba ferrite)
, and the coercive force (HC) was measured using a vibrating magnetometer.

The results are shown in Table 1.

Coercive force (+Hc) was measured by a vibrating magnetometer with a maximum applied magnetic field of 30 koe.

From Table 1, the average particle size of Aj)2Og raw material powder is 0.0.
In the samples from 05 to 1.0μ, there were no unreacted substances, and the IHC value of the powder exceeded 5 kOe.

Example 2 Purity is 99.5vt% or more and average particle size is 0.2μ-
The following a-Fe2O3, BaCO3 and an average particle size of 0
．． Using α-Am2ss from 2μ intestines, the chemical composition ratio was Ba.
O・(5,5x) F e2O3 Bottle XAI 2O3(
Here, x-0,0,2,0,5,1,0,1,5
.

2.0, 2.5, 3.0, 3.5, 4.0)
So that.

Each was weighed.

Next, these 10 types of powder were mixed in the same manner as in the example.
After drying, it was fired at 800 to 1000°C in 50°C increments. After crushing these fired powders for 3 hours using a ball mill with ethanol as a dispersion medium, the reaction products were confirmed by X-ray diffraction.

The saturation magnetization (4πIs) and coercive force (+Hc) of the powder fired on the low temperature side were measured using a vibrating magnetometer, and the results are shown in FIG.

The reaction product was confirmed by powder X-ray diffraction, and it was confirmed that there was no unreacted material in the 1M type viscous crystallized product.

These powders were also analyzed by scanning electron microscopy.

A narrow submicron particle size distribution was observed.

Moreover, in FIG. 1, one curve 11 is each AI! measured by a vibrating magnetometer. 4π■S+ curve 12 at the concentration of 2O3
is measured by a vibrating magnetometer at each Al12's concentration.
IHC is shown respectively.

The high coercive force oxide magnetic material according to Example 2 is BaO'' (
5,5X) Fe2O3''
On the other hand, 4πI5 of 2O0G or more is x-
It was found that it could be obtained with a value of 4.0 or less.

Therefore, it can be seen that the value of X within the range of x-0.2 to 4.0 is useful.

Example 3 In the same manner as in Example 2, the chemical composition ratio was (1-a) BaO
・asro・5.5 Fe2Os ・0. I Al 2
O, (where a-0, tl, 1, 0.2, 0.5
, 0.7.

0.9, 1.0), were weighed, mixed, and dried.

Next, these seven types of powders were held at 900° C. for 10 hours in the air to produce fired powders. These powders were crushed for 5 hours using a ball mill using ethanol as a dispersion medium, and then dried. It was confirmed by X-ray diffraction that these powders were only a single compound with a magnetobrambite crystal structure.

Figure 2 shows (a) saturation magnetization (4πIs) and (b) coercive force (+
This figure shows the relationship between Hc) and the ratio of each SrO concentration, and shows the results of measuring the powder obtained by the above-mentioned method using a vibrating magnetometer in the same manner as in Example 1.2.

In FIG. 2, one curve 21 is 4π1. and curve 22 is
IHC is shown, and the high coercive force oxide material according to Example 3 is (1-a) BaO・a S ro ・5
．． It is expressed as 5 Fe2O3 .0.1 AD 2Os.

As shown in this figure, Hc of 5 kOe or more is achieved in the region of a -0°05 or more.

a-1,0 is an Sr-based ferrite containing no BaO.

SrO is within the range of 0.05≦a≦1.0, Ho
Useful against increase.

Moreover, 4πI hardly changes with respect to the value of a.

Example 4 a-Fe2O3 and SrcO3 with a purity of 99.5vt% or more and an average particle size of 0.5μ or less.

0.005, 0.吋、0.05.0.10.0.5
0.1.0, 3.0.

α-AI)2Os of 5.0 μm were weighed so that the chemical composition ratios were SrO'5.3 Fe2o and 0.5 AI2O3, respectively.

Next, these eight types of powder were mixed for 20 hours using a ball mill using ethanol as a dispersion medium.

After drying, it was kept at 1000°C in the atmosphere for 2 hours.

A fired powder was produced.

Next, after crushing these fired powders in a mortar, unreacted substances (α-F e 2O s + α-AI
2's) and the reaction product (magnetobrambite type S "ferrite"), and a vibrating magnetometer (maximum applied magnetic field 3
Coercive force (+Hc) was measured by 0 KOe ).

The results are shown in Table 2.

There was no unreacted sample in which the average particle size of the AN2Oi raw material powder was 0.005 to 1.0, and the powder's and Ho were also 5koe.
A value exceeding .

Example 5 with blank space below
0.2 μm α-Al2O. using the chemical composition ratio S
ro ・(5,5-x) Fe2 o, , xA
Ω2O: (x is 0.0.2, 0.5, 1.0, 1
．． 5, 2.0.

2.5, 3.0, 8.5, 4.0).

Next, these 10 types of powder were treated in the same manner as in Example 4,
After mixing and drying, heat at 900-1400"C at 50℃, respectively.
Fired every time.

Next, using a ball mill, 2
After mixing for 0 hours and crushing the calcined acid powder for 3 hours, the reaction product was confirmed by X-ray diffraction, and the powder was found to have the same composition, clearly no unreacted substances, and was calcined at a lower temperature. The saturation magnetization (4πIs) and coercive force (+Hc) were measured using a vibrating magnetometer (maximum applied magnetic field: 30 koe). The results are shown in FIG.

IHC of 5 koe or more is obtained with X-0.1 or more.

On the other hand, 4πIs of 2O0G or more can be obtained with xm of 4.0 or less. From these facts, it can be seen that a value of X in the range of 0.1 to 4.0 is useful.

Furthermore, these powders were observed to have a narrow submicron particle size distribution using a scanning electron microscope.

Example 6 Purity is 99.8 wt% or more, average particle size is 0.2 μ■
The following a-Fe2O. , S rcOs , a-Ajl
2O, the chemical composition ratio is SrOI+(3,5-
y) Fe2Os + 2AI 2Os' yZn
o (here, y-0, 0, 1, 0, 5, 1, 0).

Next, these eight types of powders were mixed using a ball mill for 20 hours using ethanol as a dispersion medium, dried, and then held in the air at 900°C to 1150°C for 1 hour at 50°C intervals. The final product was prepared. Next, after crushing these powders in a mortar, unreacted substances (α-
Fe2Osrα-A12Os) and the reaction product (M-type Sr ferrite) were confirmed.

The results are shown in Table 3.

22, 0 in Table 3 indicates only M type Sr ferrite, △ indicates residual α-A12Os, × indicates α-Fe2O, and α-A
This shows that 12Os also remains. From the results in Table 3, it can be seen that the firing temperature is clearly lowered by ZnO substitution of 0.1 or more.

In addition, the magnetic properties (4
πIS+ lHc) with a vibrating magnetometer (maximum applied magnetic field 3
0 kOe).

The results are shown in Table 4.

From the results shown in Table 4, it can be seen that substitution of ZnO tends to slightly improve 4π■5 and slightly decrease lHc. However, even at y-1,0, +aC is 9.
5 kOe, making it a magnetic powder with an extremely high coercive force.

Example 7 In the same manner as in Example 6, the chemical composition ratio was SrO・(5,2
V) F ez Os O,5AI 2Os'
YZnO (where y-0,0,2,0,4,O,B,
0.8.

1.0 and 1.2), mixed, dried, held at 1100° C. for 10 hours, and fired.

Next, after crushing these powders, their magnetic properties (4πIs, lHc) were measured using a vibrating magnetometer.

The results are shown in FIG.

In FIG. 4, the amount of ZnO substitution is Q<y<l.

In the region of 0, 4πI5 is slightly improved and 1. HC shows a tendency to decrease but has a high value.

On the other hand, in the region of y>1.0, there is a significant improvement in 4πI,
A decrease in IHC is observed, and high coercive force magnetic powder cannot be obtained.

When we investigated the formation phase of these powders by X-ray diffraction, we found that
When y was 0 to 1.0, it was a single phase of M-type Sr ferrite, but a large amount of W-type ferrite was mixed in the powders of Y-1 and 2.

Furthermore, these powders were observed to have a narrow submicron particle size distribution using a scanning electron microscope.

Example 8 Purity is 99.8vt% or more, average particle size is 0.2μ■
The following a-Fe2O. , S rc03. a-AN 2O
, the chemical composition ratio is SrO・(5,5-x-z)
Fe2O3. xAIx O3・zTi02 (here, x
-1 and z-C1.05 and x-1.5 and 2-0), respectively, were weighed so as to have three compositions.

Next, each of these powders was mixed using a ball mill for 20 hours using ethanol as a dispersion medium, and after drying,
A fired powder was produced by holding the temperature in the air at 50°C for 2 hours in the range of 1050°C to 1350°C.

Next, after crushing these powders in a mortar, X-ray diffraction revealed unreacted substances C3rO*a-Fe2O. .

α-AI2Og, T i 02 ) is absent,
It was confirmed that M-type Sr-based ferrite was produced.

When these powders were observed using a scanning electron microscope, they were found to consist of crystal grains of about 1 μm or less.

Next, the magnetic properties of these powders (4πIs, +I'IC)
was measured using a vibrating magnetometer (maximum applied magnetic field 30 kOe).

The results are shown in FIG.

From this result, it was found that S exhibiting constant magnetic properties (4πIs, IHC) over a wide firing range by replacing with TiO2.
It can be seen that r-type ferrite powder is obtained.

Therefore, TiO in M-type Sr-based ferrite powder
It can be seen that the substitution of 2 allows the production of powders with -like magnetic properties over a wide range of calcination temperatures.

Example 9 In the same manner as in Example 8, the chemical composition ratio was SrO・(5,2
-z) Fe2O. *0.5 Al2O.・zTi0
2 (where z = 0.02.0.4, 0.8, 0
．． 8, 1°0, and 1.2), mixed, dried, and held at 50°C increments for 5 hours in the range of 1000°C to 1300°C to produce a fired powder.

Next, these powders were crushed in a mortar and then subjected to X-ray diffraction.
Although Sr type ferrite was generated, it was confirmed that Y type ferrite was mixed in z-1 and z-2. When these powders were observed using a scanning electron microscope, they were found to consist of crystal grains of about 1 μm or less.

Next, the magnetic properties (4πIs, +H6) of these powders were measured using a vibrating magnetometer (maximum applied magnetic field 30 koe). The results are shown in FIG. In the figure, 4π1. ,
, Hc are the median values of the maximum and minimum values of the measured values for each composition, and Δ4πIS and Δ1Hc represent the difference between the maximum and minimum values.

Up to z-1,0, by substitution of TiO□, Δ4π15,
ΔIHc shows a tendency to decrease significantly, but 2-1,2
Then 4πls, IHC decrease and 4x1. .

Δ　IHC increased significantly.

Therefore, TiO in M-type Sr-based ferrite powder
It can be said that the substitution effect of 2 is significant in the range of x-0.1 to 1.0.

Example 10 Purity is 99.8wt% or more and average particle size is 0.2μ-
The following a F e2OB , S rcO3, a
Using All2O3, ZnO, and TiO2, the chemical composition ratio is SrO・(3,5-y-z)Fe2O3・2
Ag2O3 .yZnO-zTiOz: Three types of compositions were weighed so that (here, y and 2 were 0. y was 0.5 and 2 was 0. y was 0.5 and 2 was 0.3).

Next, each of these powders was mixed using a ball mill for 20 hours using ethanol as a dispersion medium, dried, and then held in the air at 950°C to 1130°C for 1 hour at each 50°C to produce a fired powder. .

Next, after crushing these powders in a mortar, unreacted substances (a-Fe2O3. α-Aj)2O3 were determined by X-ray diffraction.
) and reaction products (M-type Sr ferrite and other hexagonal ferrites) were confirmed.

The results are shown in Table 5.

Table 5 shows the powder magnetic properties of each composition fired at 1150°C (4π
I,, +Hc) with a vibrating magnetometer (maximum applied magnetic field 30
kOe).

The results are shown in Table 6.

In Table 6, Q represents only M-type Sr ferrite, and Δ represents α-Ap2O.
remains, × indicates both a-Fe2O3 and a-A12O3 remain, and ☆ indicates coexistence of M-type Sr ferrite and W-type ferrite.

From the above results, it can be seen that by containing a combination of ZnO and T i 02, the sintering temperature is clearly lowered and the temperature range in which only the M-type Sr ferrite single phase is formed is expanded.

From the above results, it can be seen that although IHC slightly decreases by ZnO substitution, 4πIs improves, and even if TiO2 is substituted, the magnetic properties do not decrease.

Therefore, S rO−F e2Os −Aj! 2O
By including TiO□ in a part of s-ZnO-based M-type Sr ferrite, the reaction formation temperature is lowered and the single-phase formation temperature range is expanded without deterioration of magnetic properties. .

Example 11 In the same manner as in Example, the chemical composition ratio was SrO・(4,5-
y-z) Fe2Os φAI 2Os ・VZno-
zTio2 (where y and 2 are 0, y is 0 and 2 is 0
．． After weighing the three compositions so that 5.3/ is 0.3 and 2 is 0.5), they are mixed, dried, and heated to 1000 ° C.
The temperature was maintained at 50° C. for 5 hours in the range of 1250° C. to produce a fired powder.

Next, after crushing these powders in a mortar, unreacted substances (SrO*a-Fe2O., α-A j?
It was confirmed that M-type S' type ferrite was generated without the presence of 2O3, ZnOlT i 02 ).

Furthermore, when these powders were observed using a scanning electron microscope, they were found to consist of crystal grains with a thickness of 1 μm or less.

Next, the magnetic properties of these powders (4πIg, +Hc)
was measured using a vibrating magnetometer.

The results are shown in FIG.

From this result, it is clear that ZnO and Ti are present in a part of the Sr-based ferrite.
It can be seen that by containing O2, a powder with stable magnetic properties over a wide firing temperature range and a high 4πIS can be obtained.

Example 12 In the same manner as in Example 10, the chemical composition ratio was 5rO (5,2
-Y Z) F e2O3” 0.5 Al10s・
yZnO-zTi02 (here y-z, y+z
−0,0,2,0,4,0,8,0,8,1,0,1,
2゜1.4) After weighing each, mix,
Dry and heat at 50°C intervals in the range of 950°C to 1250°C.
The mixture was held for 10 hours to produce a fired powder.

Next, after crushing these powders in a mortar, X-ray diffraction revealed that they were M-type Sr-based ferrite single phase in the range of y+z-0 to 1.2, but the powders in y+z-1,4 It was confirmed that a small amount of W-phase ferrite was present in the powder fired at 1250°C.

Furthermore, when these powders were observed using a scanning electron microscope, they were found to consist of crystal grains of about 1.5 μm or less.

Next, the magnetic properties (4π1., H6) of these powders were measured using a vibrating magnetometer.

The results are shown in FIG.

In the figure, 4πIS+ IHc is the median of the maximum and minimum values of the measured values for each composition, and Δ4π'5+
ΔIHC represents the difference between the maximum value and the minimum value. z
+y-0, In the range of 1 to 1.3, Δ4πIs, ΔI
A significant decrease in Hc was observed, indicating that Sr-based ferrite powder with stable magnetic properties could be obtained over a wide firing temperature range. Moreover, while maintaining high Hc, 4πI5
has also increased significantly.

Example 13 Purity is 99.1lvt% or more, average particle size is 0.2μ or less (Da-Fe2O., Srco, a-AN2
It uses O, ZnO, TiO2, and the chemical composition ratio is Sro.
・3.8 Fe2O3 0.5 AN72O3 aO
, 7ZnO・0.7 T i O□, mixed and dried, and the atmosphere was changed to air and 0
2/ (02+N2) is 30.40.50.60.80
．． The concentration was adjusted to 100 vol% and each was held for 5 hours to obtain a fired powder.

Note that the flow rate of this atmosphere was set to IN/s1n.

Next, after crushing these powders in a mortar, the formed phase was confirmed by X-ray diffraction.

The magnetic properties (4πIs, IHc) of the powder were measured using a vibrating magnetometer by applying a magnetic field of about 30 kOe.

The results are shown in Table 7.

When these powders were observed using a scanning electron microscope, it was found that 1
Most of the particles were ~1.5 μι.

As described above, when 02 in the firing atmosphere is 50 vol% or more, W-type ferrite, which is a different phase, disappears, and 1Hc is significantly improved.

Below is the margin Example 14 S ro created in Example 12 (5,2-y-z)
Fe2 o3 ・0.5Al2O3 ・yZnO-zT
iO□ (where y, z”0.2, 0.7)
Two kinds of powders having the following composition and fired at 1250° C. were ground and mixed using a ball mill so that the particles had a diameter of about 0.7 μm or less.

Next, these finely pulverized powders were heated at 800°C, 900°C, and
Heat treatment was performed at 00°C, 1100°C, 1300°C, and 1400°C in air for about 2 hours.

These powders consisted of grains of about 2 micron layers or less. Further, a small amount of W phase ferrite that was confirmed in the fired components of y, z-0, 7 disappeared.

Next, the magnetic properties of these powders (4πIs, IHC)
was measured. The results are shown in FIG.

In the figure, ○ mark (solid line) is y, z-0,2, △ mark (broken line)
represents a powder with a composition of y, z=0.7.

After finely pulverizing the fired powder, heat treatment is applied to produce IHc.
clearly improved, and it can be seen that heat treatment in the range of 850 to 1350°C is particularly effective. Note that 1350° C. here is a value 100° C. higher than the firing temperature.

Therefore, in the composition range of the present invention, heat treatment within this temperature range is effective.

In addition, in the examples, as the raw material powder of ferrite,
BaCO3,5rCO,, a-Fe2Os, a
Although only the case where AN 2Os, ZnO, and T i 02 are used has been described, the present invention also relates to the case where BaOFe2
Os An 2Os, BaOS ro Fe
2O3Af12OsrSrO-Fe2O3-AI 2O
x, SrOFe2 o, Afl2O3 Z
nO, BaO-Fe2O3-Al2O3-ZnO.

SrOFe2Os AD 2O3 ZnOTiO2
, BaO-Fe2Os-AI2O. -ZnO-T
Any M-based ferrite containing iO2 as a main component can be applied.

On the other hand, the raw material powder is also B a O, B a (OH) 2
.

BaSO4, Sr (OH)2. SrO,5rCjJ2
, SrSO4,a-Fe2OOH,Fe(OH)s
, 7 F e2O3 , AII(OH) 3
.

ZnCO3, ZnTi (SO4)2. Ti
(S.

4) In the second firing process, BaOFezO3Afl 2
Og, BaO-8ro-Fe2O3-Al
2O3, Sro-Fe2Os-AD
20s + Sr.

-Fe20s AI2O3-ZnO,BaO
Fe2 03 AM 2 03 ZnO, Ba
0-S rOF e2Os Al 2 0g
-ZnO, S ro-Fe 2Os AI
2Os TiO2, BaO-Fe20s-A
D20s-T i O2, BaO-8r
O-Fe203-AI20s TiO2
, 5rO-F e2Os AN 2 03
Zn0-T i 02 , BaO-F e2O
3 -AI 2 0s -ZnO-T i 0
2, BaO-8rO-Fe2O3 AIIzOs-Z
It is easy to understand that anything that produces nO-TiO2 or the like is included in the present invention from the ferrite production reaction.

In addition to the manufacturing method of the present invention, in which raw material powders are mixed and then fired, methods for manufacturing magnetobrambite-type ferrite powder include a coprecipitation method, an organometallic salt method, a vitrification precipitation method, etc. The manufacturing method of the former two types is essentially the same as that of the present invention since compound crystals are generated by firing.

Further, those skilled in the art will easily understand that the vitrification precipitation method is considered a part of the present invention if the composition of the crystallized ferrite powder is included in the present invention.

[Effects of the Invention] As described above, according to the present invention, the coercive force of the magnetoblanbite type ferrite made of an Al and Sr type ferrite material, which is inexpensive and stable, can be reduced by replacing a part of this ferrite with Al12Os. It is possible to provide an oxide magnetic material powder having a high coercive force and a method for producing the same.

Further, according to the present invention, the price can be kept low and stable.

and a part of Sr-based ferrite material Fe2O, Ag2O
The M-type ferrite material substituted with 3 was replaced with ZnO and TiO
By appropriately adding at least one type of 2, it is possible to manufacture the material to exhibit constant magnetic properties over a wide firing temperature range, and an improvement in the magnetic properties (4πIs) can also be expected.

According to the present invention, by containing 50 vol% or more of oxygen in the firing atmosphere in which the raw material powder is fired, it is possible to reduce the cost and improve the coercive force of stable magnetopran/kuite type ferrite, which has a high coercive force. A method for producing magnetic material powder can be provided. In particular, among magnetobrambite ferrites, a part of Fe2O is replaced with Al2O.
Magnetobrambite-type ferrite (M-type ferrite) materials substituted with 3 can be manufactured over a wide manufacturing range to exhibit similar magnetic properties.

[Brief explanation of drawings]

FIG. 1(a) shows M-type Ba ferrite Babe (5,5-x)Fe2O3XAl2O according to Example 2 of the present invention.
FIG. 1(b) is a diagram showing the relationship between the AD 2Os content and the saturation magnetization (4πIs) of No. 3, and FIG.
” Al2Os content and coercive force (+
FIG. 2(a) is a diagram showing the relationship between Hc) and M-type B-based ferrite (1-a) BaO-a according to Example 3 of the present invention.
Sro・5.5 Fe2O3 ・0.1 A12O3
Figure 2<b> is a diagram showing the relationship between the SrO content and the saturation magnetization (4πIs) of M-type Ba according to Example 3 of the present invention.
Ferrite (1-a) BaOeaSro・5.5 Fe
2O3 ・0.1 A diagram showing the relationship between the SrO content and coercive force (+Hc) of AN 2Os, and FIG. 4
4th diagram showing the relationship between πIs) and coercive force (+Hc)
The figure shows Sr-based ferrite (S ro
・(5,2V) Fe2Os ・0.5Aρ,O,・
FIG. 2 is a diagram showing the relationship between the ZnO content (y) of yZnO), the saturation magnetization (4πIS), and coercive force (+Hc) of ferrite powder. FIG. 5 shows the Sr-based ferrite (5,5-x-
z) Fe2O3 IxA(72O, *zTiO (where x-1 is z-0,05 and x-1,5 is 2-03
This is a diagram showing the relationship between the firing temperature of the powder and the magnetic properties (4π'S+ +Hc) for the raw material composition (composition). (−
The dotted line) represents the composition of 2-0 at x-1,5, and the △ mark (dotted line) represents the composition of z-0,5 at x-1,0. FIG. 6 shows the Sr-based ferrite SrO・(5
,2-Z) Fe2O3 ・0.5 Al2O3z
Tio2 (where z-0,0,2,0,4,0,6
. 0.8, 1.0, 1.2), the median value of the maximum and minimum values of the magnetic properties (4π'S+ +Hc) of the powder fired in the range of 1000℃ to 1300℃ 4πS+ IHC and its difference Δ4π■s. A diagram showing the relationship between ΔIHC and TlO2 substitution value 2,
Figure 7 shows the Sr-based ferrite (4,5y
z) Fe2O3 #A12O3 ・yZnO-zT
In the raw material mixture composition i02, 1100 to 1300
Calcination temperature and magnetic properties (4πI) of powders fired in the range of °C
s, +Hc). In the figure, the O mark (solid line) indicates a composition where y and 2 are 0, and the inside of the mouth (-dotted line) indicates a composition where y is 0.
The symbol Δ (dotted line) represents a composition in which y is 0.3 and 2 is 0.5. FIG. 8 shows the Sr-based ferrite SrO・(5
,2y z) Fe2O3・0.5 AI 2O・y
ZnO-27102 (here, Y-z, y+z=0
．． 0.2, 0.4, 0.6. , 0.8 , 1.0
, 12, 1.4), 95
Magnetic properties of fired powder in the range of 0"C to 1250"C (4
The median value of the maximum and minimum values of π'S, +Hc) 4πIs
A diagram showing the relationship between ++H (and the difference Δ4yr I5. Δ1Hc and the content of ZnO and TlO2 (y+z), FIG. 9 shows the relationship between the Sr ferrite S r · in Example 14
(5,2-y-z) F eo3・0.5 All 2
O, ・yZno-2Tio2 (where, V, z -0
゜2 or 0.7), 1250
After finely pulverizing and mixing the powder fired at 800 to 140 °C
Magnetic properties (4πIs,
+Hc) in the figure. The mark (solid line) indicates that y and 2 are 0.
2, and the △ symbol (broken line) represents a powder with a composition where y and 2 are 0.7. Figure 3 (A12O3) Collection 1 Figure (a) Z (AlzO3) (b) Figure (AI!2 (b) Figure Sr () [5,2-”/ ) Fe2O3-0.5
Af2O3-'f Zn0y (Z, ol Fig. 2 <a> α (SrO) Fig. 5 Firing temperature (0C) Fig. 6 5rC) (5,2-Z) Fe2O305A1zO3ZT
L○2 Z (TlO2) Fig. 8 S, ○(5,24-Z) Fe2O30.5A1zO3: 1nOITLO2 (However = l) (μ㼼Z) Fig. 7 5rO (4,5'j 1) Fez ○3 Al2O31
JZ7LOZTLO2 firing temperature (0C) Fig. 95r()(5,2-M-Z)Fe2O30.5A12O
3 SoZuOZTjOz silent processing temperature (℃) Procedural amendment (voluntary) July 4, 1990

Claims (10)

[Claims] 1. General formula, (1-a) BaO・aSrO・(6-n-
x) Fe_2O_3・xAl_2O_3: (However, n=
0 to 1.5, and when 0≦a<0.05, 0.2≦x≦4
．． 0, when 0.05≦a≦1.0, 0.1≦x≦4.0
) An oxide magnetic material powder characterized by having a chemical composition represented by: 2. General formula, (1-a) BaO・aSrO・(6-n-
x-y-z) Fe_2O_3・xAl_2O_3:yZ
nO・zTiO_2: (However, n=0 to 1.5, 0≦y
≦1.0, 0≦z≦1.0, 0.1≦y+z≦1.3, and when 0≦a<0.05, 0.2≦x≦4.0, -05
An oxide magnetic material powder having a chemical composition expressed as (0.1≦x≦4.0 when ≦a≦1.0). 3. In the manufacturing method of oxide magnetic material powder, the general formula,
(1-a) BaO・aSrO・(6-n-x)Fe_2
O_3・xAl_2O_3: (However, when n=0 to 1.5 and 0≦a<0.05, 0.2≦x≦4.0, 0.0
5≦a≦1.0, 0.1≦x≦4.0) A preparatory step of preparing a starting powder by mixing and drying raw material powders so as to have a chemical composition expressed by 0.1≦x≦4.0); 1. A method for producing oxide magnetic material powder, comprising a firing step of firing the powder in a firing atmosphere to produce fired powder. 4. In the method for producing oxide magnetic material powder according to claim 3, Al_2O_3 of the raw material powder is 0.005 to 1.0.
A method for producing an oxide magnetic material powder characterized by having an average particle size of μ. 5. The method for producing oxide magnetic material powder according to claim 3 or 4, wherein the firing atmosphere contains 50 vol% or more of oxygen. 6. In the method for producing oxide magnetic material powder according to any one of claims 3 to 5, after the sintered powder is finely pulverized and mixed, the temperature does not exceed the predetermined sintering temperature by 100°C or more. 1. A method for producing oxide magnetic material powder, comprising a heat treatment step of performing heat treatment within a range. 7. In the manufacturing method of oxide magnetic material powder, the general formula,
(1-a) BaO・aSrO・(6-n-x-y-z)
Fe_2O_3・xAl_2O_3:yZnO・zTi
O_2: (However, n=0 to 1.5, 0≦y≦1.0,0
≦z≦1.0, 0.1≦y+z≦1.3, 0≦a<0
．． When 05, 0.2≦x≦4.0, 0.05≦a≦1.
a preparation step of preparing a starting powder by mixing and drying raw material powders so that the chemical composition is expressed as 0.1≦x≦4.0); 1. A method for producing oxide magnetic material powder, comprising: firing at a predetermined firing temperature to produce a fired powder. 8. In the method for producing oxide magnetic material powder according to claim 7, Al_2O_3 of the raw material powder is 0.005 to 1.0.
A method for producing an oxide magnetic material powder characterized by having an average particle size of μ. 9. 9. The method for producing oxide magnetic material powder according to claim 7 or 8, wherein the firing atmosphere contains 50 vol% or more of oxygen. 10. In the method for producing oxide magnetic material powder according to any one of claims 7 to 9, after the fired powder is finely pulverized and mixed, the temperature does not exceed the predetermined firing temperature by 100°C or more. 1. A method for producing oxide magnetic material powder, comprising a heat treatment step of performing heat treatment within a range.